An endemic need of modern society is the need to communicate. Data regularly must be communicated, sometimes between widely dispersed locations. Communication systems, formed at a minimum of sending and receiving stations interconnected by way of a communication channel, are used to effectuate the communications. Many different types of communication services are regularly effectuated by large numbers of users through use of many varied types of communication systems.
New types of communication systems have been developed and implemented as a result of scientific discoveries and technological advancements. Technological advancements continue, and their deployment in communication systems correspondingly continue. New communication systems are developed, and improvements to existing communication systems are made, as a result of such deployment. Such new, as well as improved, communication systems permit the effectuation of new types of communication services or the effectuation of such services in manners not previously possible.
Amongst the technological advancements that have been deployed in communication systems are advancements in digital communication techniques. Several advantages are inherent in communication systems that utilize digital communication techniques. Perhaps most significantly, the use of digital communication techniques generally provide for improved communication efficiencies. That is to say, the communication capacity of a communication system that utilizes digital communication techniques is generally significantly greater than the communication capacity permitted in a communication system that utilizes analog communication techniques.
A radio communication system is an exemplary type of communication system. A radio communication system is referred to as such as the communication channel that interconnects the sending and receiving stations is defined upon a radio link, at least for a portion of a communication path extending between the communication stations of the radio communication system.
A radio communication system provides various advantages relative to a conventional, wireline communication system. For instance, implementation of a radio communication system is generally performed more economically than a wireline counterpart. That is to say, the infrastructure costs associated with a radio communication system are generally less than the costs associated with installation of a network infrastructure of a wireline communication system. So, for reasons associated with initial deployment costs, radio communication systems are sometimes preferred over their wireline counterparts. Also, a radio communication system can be implemented as a mobile communication system, thereby to provide mobility of communications. Communications in such a system are possible, from and between, locations at which the use of a conventional, wireline communication system would be impractical. And, communications between moving communication stations, herein referred to as mobile nodes, is sometimes also possible.
A cellular communication system is a type of radio communication system that has achieved wide levels of usage. The networks of several different types of cellular communication systems have been installed throughout significant geographical areas and encompass significant portions of the populated areas of the world. Successive generations of cellular communication systems have been developed and deployed, and successor-generation systems are undergoing deployment or are under development. So-called, first generation (1G) cellular communication systems generally utilize analog communication techniques and provide for voice communications using circuit-switched connections. So-called, second generation (2G) cellular communication systems generally utilize digital communication techniques and provide for some data services. 2.5G (second and a half generation) and 3G (third generation) systems are currently undergoing deployment, and successor-generation systems are under development. These later-generation systems generally provide, or are intended to provide, amongst other things, more extensive data communication services.
For many, use of a cellular communication system through which to communicate has become an essential, sometimes even the primary, means by which to communicate telephonically. As indicated above, cellular communication systems were initially used primarily for voice communications utilizing analog techniques. But, their use is increasingly to effectuate data communication services, and development of new-generation systems are, in no small part, predicated upon their ability to provide for the effectuation of data communication services.
In most cellular communication systems, various control procedures must be carried out in order for a mobile node to be operable to communicate by way of the communication network of the communication system. Other radio communication systems sometimes also have analogous control procedures that analogously must be carried out in order for the mobile node to be able to communicate by way of the associated communication network. While some control procedures are specific to the particular type of communication service that is to be carried out, other control procedures must be carried out irrespective of the communication service that is to be carried out. And, more specifically, some control procedures must be carried out merely to permit the mobile node to be available for subsequent use, that is, to be available subsequently to perform a communication service.
Because a mobile node is not maintained in an affixed connection with a network by way of a wireline connection, the mobile node must, in some manner, find, select and become attached to the network with which the mobile node is to communicate. A network searching procedure is performed by the mobile node to locate and select the selected network with which the mobile node is to become attached or otherwise communicate. Control signaling is required to be generated by the mobile node pursuant to the network searching and selection procedure.
And, once the mobile node locates the selected network through the searching procedure, the mobile node must become registered with the network. Through the registration procedure, various indicia associated with the mobile node are provided to the network, such as the identity of the mobile node and the location of a home network associated with the mobile node. Various procedures are sometimes subsumed into the registration procedure. For instance, authentication procedures sometimes are considered to be part of a registration procedure. In an authentication procedure, the identity of the mobile node is verified, i.e., authenticated. Improper, or fraudulent, access to the network is prevented. Again, control signaling is required to be generated by the mobile node pursuant to the registration procedure. Registration procedures are sometimes repeated at selected intervals subsequent to initial registration by the mobile node when the mobile node is initially powered-on.
Additional procedures are carried out subsequent to registration. For instance, routing area updating and location updating procedures are selectably performed by the mobile node. As a mobile node is mobile, the mobile node might well be initially positioned at one location and thereafter travel to another location. Routing areas and location areas are defined in some cellular communication systems. Routing areas and location areas are typically associated with groups of cells. When the mobile node passes into a new routing area or a new location area, the mobile node performs a routing area update or location area update procedure, as appropriate. In such a procedure, the network is alerted to the change of positioning of the mobile node out of one area and into another area. Subsequent communications with the mobile node are able more efficiently and quickly to be directed through the network for delivery to the mobile node. Again, control signaling is required to be generated by the mobile node pursuant to the routing area update and the location area update procedures.
The mobile node, typically, is powered by a portable power supply, of limited energy-storage capacity. When the portable power supply, i.e., a battery power supply, is depleted of stored energy, the mobile node no longer functions properly, if at all. And, the portable power supply must be replaced or recharged to permit continued use of the mobile node. User satisfaction with the mobile node is, at least in some respect, dependent on the longevity of the portable power supply. So, efforts are regularly made to reduce the power consumption rate of the mobile node.
Each time in which control signaling is generated at the mobile node, power is consumed, and the stored energy of the battery power supply is depleted. While the control signaling to perform the various control procedures is necessary to permit operation of the mobile node in the communication system, problems occur when the mobile node is positioned in an area of marginal, or no, coverage by the communication network. When so-positioned, signals generated by the mobile node are unlikely, or are unable, to be delivered successfully to the network part.
When, for instance, a network selection or a registration procedure is not successfully performed by a conventional mobile node, the mobile node continues to attempt the procedure, generating control signals in such attempts. The continued generation of the control signals is power-consumptive and depletes the stored energy of the battery power supply that typically powers the mobile node. And, more frequent replacement, or recharging of, the battery power supply is necessitated.
Accordingly, if a manner could be provided by which better to control when to permit control signaling to be generated at a mobile node, increased longevity of the battery power supply would be provided, and improved user satisfaction of use of the mobile node would be possible.
It is in light of this background information related to communications in a radio communication system that the significant improvements of the present invention have evolved.